BACKGROUND/AIMSX-linked adrenal hypoplasia congenita (AHC) is typically characterized by a DAX-1 gene mutation and hypogonadotropic hypogonadism. However, rare cases with precocious puberty or normal puberty have been reported. Currently, the mechanism of action of the DAX-1 gene on puberty is not clearly known.CASE REPORTWe report a male who was diagnosed as having AHC in the newborn period and detected as having stop codon Q155 X mutation in the DAX-1 gene. This subject developed central precocious puberty when he was 9 months old.RESULTSThis paper is the first case report of AHC, central precocious puberty and a mutation in the DAX-1 gene. DAX-1 gene mutations can result in various phenotypes.CONCLUSIONIn cases with AHC, central precocious puberty can develop rather than hypogonadotropic hypogonadism, which is the most frequently observed puberty disorder related to DAX-1 gene mutations.